“Worse Than an Exchange Hack”: Samson Mow Warns Coldcard RNG Vulnerability Hits Hardcore HODLers

Key Takeaways

• Coldcard RNG vulnerability hits careful self-custody users harder than any exchange hack, Samson Mow warns.  
• After Mk3 losses, attackers now actively drain Mk4, Mk5 and Q wallets worldwide.  
• Multi-vendor multisig remains the only real defense against single-point hardware failures.

In a recent X thread, Samson Mow issued a warning that the Coldcard RNG vulnerability is worse than an exchange hack for careful self-custody users. After the initial Mk3 drainage, attackers now actively drain Coldcard Mk4 and Mk5 wallets on affected seeds. Holders who generated keys on older firmware face irreversible losses. Mow recommended documentation, police reports and strict avoidance of recovery scams. He stressed that true self-custody requires multiple vendors.

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Coldcard RNG Vulnerability: Samson Mow Sends Message to Devastated Sovereign Bitcoin Holders

Samson Mow addressed the Coldcard RNG vulnerability that emptied hundreds of Mk3 wallets in late July. Attackers exploited weak Bitcoin seed entropy created on flawed firmware dating back to 2021. Nearly 600 bitcoin left carefully secured devices overnight.

Mow told affected owners the losses cut deeper than any exchange failure. About it, he mentioned:

“The COLDCARD RNG vulnerability may be worse than an exchange hack. It hit at the core of sovereign Bitcoin holders – it struck those who did all the research, understood why self-custody is important, and didn’t keep coins on exchanges.”

The hardware wallet security flaw left single-signature Mk3 seeds open to brute-force attacks. Funds moved in rapid sweeps to a handful of addresses. Early reports confirmed the scale across roughly 500 wallets.  

Mow urged victims to record every detail and file police reports at once. He warned against anyone promising recovery. Keep original devices and seeds safe. A possible freeze later may require proof of ownership. He repeated a long-standing call for multi-vendor multisig. One brand alone creates fatal exposure and shows that Bitcoin self-custody risks exist.

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Immediate Threat: Active Coldcard Mk4 drain Spreads to Mk5 and Q Devices Worldwide

The Coldcard Mk4 drain has now expanded to Mk5 and Q models across the globe. Attackers target seeds created under the Coldcard RNG vulnerability on older firmware. On-chain watchers confirmed fresh sweeps overnight from test wallets left with small balances. Similar drainage campaigns recently hit dormant Ethereum addresses through legacy code weaknesses. 

The same pattern now appears in Bitcoin hardware wallets. Users face rising Bitcoin self-custody risks as the attacks continue without pause.  The hardware wallet security flaw stems from weak Bitcoin seed entropy that never reached full strength. Mk4 devices offered partial gains over earlier versions yet still fell short of safe thresholds. Mk5 and Q units share the same limited construction.

Owners who generated seeds without dice rolls or strong passphrases remain exposed. Funds leave addresses in coordinated batches toward known collection points. Security researchers urge immediate migration to new seeds on patched devices. Time remains critical for anyone still holding balances on affected hardware.

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